Embryo Stages Flashcards
(16 cards)
Isolecithal cleavage
Evenly distributed yolk, cleaves equal parts
“ISO” = Same
What happens during cell cleavage?
Period of rapid cell division with no growth.
Produces building blocks for future development.
Mesolecithal cleavage
Moderate vegetal yolk disposition
Displaced radial cleavage
Telolecithal cleavage
Incomplete.
Dense yolk throughout.
Cleavage only near top of cell
Centrolecithal cleavage
Yolk in center of egg.
Superficial cleavage.
What is the Blastula stage?
Grouping of cells with hollow hole in center
Hollow hole in blastula?
Blastocoele
What happens during Gastrulation?
Cells divide and move to form multiple distinct cell layers.
Cells become less uniform.
Cell - cell contacts form.
Cells placed in proper orientation for organogenesis.
What are the three germ layers?
Ectoderm, mesoderm, and endoderm.
What is morphogenesis?
This movement of cells resulting in the formation of embryonic structures.
What is invagination?
Outer cell layer pulled in like a “V”
What is involution?
Cells break the cirlcle, fold in and move back around cell, always staying in contact with the outer later.
What is ingression?
Layer of cells squeeze individual cells in and ogre move them from together chain, make circle smaller.
What is delamination?
Bringing a whole layer of cells to the inside.
What is epiboly?
Cells dividing at the too push the rest of the cells down and around to the inside.
What is the first visible structure to from in organogenesis?
The neural tube
Future spinal cord.
